Catalytic reaction apparatus



March 24, 1953 H. F. PETERS CATALYTIC REACTION APPARATUS 2 SHEETS-SHEET1 Original Filed Oct. 13, 1947 n I p p v v INVENTOR. BY MRRYF PETERS A7' TOEWEYS H. F. PETERS CATALYTIC REACTION APPARATUS March 24, 1953Ofiginal Filed 001... 13, 1947 2 SHEETS- SHEET 2 INVENTOR. I l 4BR) /TPETERS BY A TTOR/VEYS Reissuecl Mar. 24, 1953 Re,

UNITED STATES PATENT OFFICE CATALYTIC REACTION APPARATUS Harry F.Peters, Haddonfield, N. J., assignor to Sun Oil Company, Philadelphia,Pa., a corporation of New Jersey Original No. 2,475,855, dated July 12,1949, Serial No. 779,518, October 13, 1947. Application for reissue July12, 1950, Serial No. 173,267

' Matter enclosed in heavy brackets appears in the original patent butforms no part of this reissue specification; matter printed in italicsindicates the additions made by reissue.

4 Claims.

This invention relates to improved apparatus for conducting catalyticreactions and more particularly to apparatus for carrying out catalyticprocesses involving alternate endothermic and companying drawings, inwhich:

Figure 1 is an elevational view, partly in section, of one form of theimproved catalytic reactor;

Figure 2 is a top view of the reactor on the line exothermic reactions.A typical process of this 2-2 of Figure 1;

type is the catalytic conversion of hydrocarbons Figures 3-A and 3-13are details of means for in a cyclic operation, wherein hydrocarbons aresupporting the catalyst trays within the reactor; caused to reactendothermically in the presence Figure 4 is an elevational view, partlyin secof a catalytic contact mass, causing deposition of tion, of amodified form of the reactor including carbonaceous deposits on the masswhich reduce an improved internal spray arrangement;

the catalytic activity, and the catalyst is then Figure 5 is anelevational view, partly in secreactivated by burnin off thecarbonaceous mation, of another modified form of the reactor interial.The catalytic cracking of higher boiling eluding external means forflowing reactants from hydrocarbons to lower boiling hydrocarbons is aone tray to the next; and

specific example of this type of process. Other Figure 6 is anelevational view, partly in seeexamples are reforming, dehydrogenationand the tion, of still another modification of the reactor like.including external flow means.

More specifically, the present invention is con- Referring first toFigures 1 and 2 of the drawcerned with an improved catalytic reactor foruse ings, the reactor comprises a vertically elongated in a stationarybed type of operation, wherein the cylindrical outer shell l0 having aninlet conneccatalyst is employed in the form of a plurality of tion ornozzle l I at the top and an outlet connecstationary beds within thereactor and is regention or nozzle l2 at the bottom. A plurality oferated periodically in situ by passing hot oxygentrays are positionedwithin the shell in superposed containing gases through the several bedsThe relation for maintaining several separate beds of reactor isespecially adapted for use in that type catalytic contact'material. Forpurpose of illusof catalytic conversion generally referred to intration, the reactor is shown in Figure 1 as having the art as adiabaticoperation. By this is meant four such beds indicated generally as [3,l4, l5 that both the endothermic and exothermic reacand I6, but it willbe understood that any suitable tions are carried out without the use ofa circulator desired number of beds may be provided, The ing convectivefluid for supplying heat to, Or retrays are annular shaped and arepositionedesmoving heat from, the reaction zone by indirect sentiallyconcentric to the outer shell it and in heat transfer. In other Words,in such adiabatic spaced apart relation to each other. Since all ofoperation the heat required for the endothermic the trays may be ofsimilar construction the folreaction is supplied either as sensible heatof the lowing description thereof is made with specific reactantsentering the reaction zone or as heat reference only to the top tray.stored in the contact mass during the previous Each of the trayscomprises an inner wall H regeneration period, while the heat evolveddurwhich is continually perforated to permit flow of ing the exothermicreaction either is stored in the fiuid therethrough and an outer wall18, likewise contact mass for use in the subsequent on-streamperforated, which is of lesser diameter than the period or else isremoved from the reaction zone shell It so as to provide an annularspace [9 bein the form of sensible heat of the efliuent regentween theouter wall [8 and the shell. An imeration gases. The reaction apparatusaccording perforate cover member/28 extends over the top to the presentinvention is especially adapted for of the tray and also serves to closeoff the top of storage within the contact mas of a large prothe centralspace 2| within the tray. ac y 13 portion of the exothermic heat evolvedduring the constructed with a convex bottom formed by regenerationperiod for use during the subsemeans of animperforate conxex bottommember quent on-stream period. The apparatus is 22. This arrangementpermits the weight of the adapted for the utilization of this storedheat bed of contact material to be carried on the botnot only as heat ofreaction but also as heat for tom of the tray Without direct supportfrom beevaporating hydrocarbon charge material introneath. Convex bottommember 22 has an openduced between the several beds of catalytic coningin its center corresponding .to central space tact mass during thesubsequent on-stream 2| Within the traysoas to permit fluids passing -1from the bed intothe central space to flow there- The features andadvantages of the invention from downwardly to the next bed of contactcan best be understood by reference to th acmaterial.

The trays are supported Within the reactor by circumferential supportmeans positioned within the outer annular space [9 between the tray andthe shell 10 at or near one end of the annular space. As shown in Figure1, the support means are positioned at the bottom of the annular space.Such support means are adapted not only to support the weight of thetray and the contact material therein upon the outer shell but also toclose off annular space [9 at its bottom in order to direct the flow ofreactants in the desired manner through the bed. As illustrated in moredetail in Figures 3-A and 3-B, such support means may comprise a lowersupport ring 25 welded to the outer shell to and reinforced by means ofa plurality of suitable braces 21 positioned around the inside of outershell I0, and an upper support ring, illustrated at 28, which is securedto the outer wall l8 of the tray and is likewise provided with aplurality of braces 29. As shown in Figure 3-A the upper support ring28-a may be welded to the outer wall 18 of the tray; or in another formas shown in Figure 3-B, the upper support ring 28-h may be formed as anintegral part of a circular member 30 which is adapted to serve as aportion of the outer wall of the tray. In this second form wall member30, carrying support ring 28b as an integral part thereof, is welded tothe bottom of outer perforate wall I8 and also to convex bottom member22. The upper support ring 28 is adapted to rest upon the lower supportring 26 so as to carry the weight of the tray and bed of contactmaterial upon the outer shell It] and also to close off the bottom ofthe annular space between the tray and the outer shell to preventreactants from flowing around the bed rather than through it. Theelimination of any'necessity for beams or other support means positionedbeneath the trays is one of the distinctly advantageous featuresresulting from the above described arrangement.

The trays are filled with a granular contact material which preferablyis a mixture of catalyst (for example, a silica-alumina type catalyst ifthe reaction to be conducted is the cracking of hydrocarbons) and agranular inert material of high heat absorbing capacity (for example,artificially fused oxide such as described in Houdry Patent No.2,414,812). The proportion of catalyst to heat absorbing material mayvary widely depending upon the particular materials used and the amountof heat that it is desired to store in the contact mass during eachcycle, but generally will be within the range of 1:5 to 3:1. With thetray construction as shown in Figure 1 and with the general direction ofreact-ant flow from top to bottom of the reactor, it will be apparentthat the flow of reactants through each bed will be in .a generallyhorizontal direction inwardly. Thus, reactants will enter each bed fromthe annular space l9 through the perforations in outer wall I8 and willleave each bed by issuing through the perforations in inner wall ll intothe central space =2 l, thence flowing downwardly to the next lower bedand passing there-through in like manner.

In the space between adjacent beds of catalytic contact material, meansare provided for introducing additional amounts of reactants into thevapor stream in the form of a fine liquid spray. Such means may compriseinlet lines 23-a, 23-h and 23-0 having liquid spray nozzles 24-a, 24-10and 2 4-0, respectively, preferably pointing upwardly toward the centralspace of the tray above so as to provide intimate contact 4 between theinjected liquid spray and the Va pors flowing down from the tray abovebefore the mixture passes to the next lower tray.

It will be noted that the catalyst beds l3, l4, l5 and it are ofdifferent heights, increasing in the direction of flow through thereactor. This is distinctly preferable in order to compensate for theadditional reactants introduced as spray between the beds so that thespace velocities of reactants passing through the several catalyst bedswill be about the same. In operation, during the on-stream orendothermic reaction period, hydrocarbon reactants are introduced intothe top of the reactor through inlet H and pass into the outer annularspace I9 and inwardly through the uppermost catalyst bed I3 and into thecentral space 21. In passing through bed IS the reactants will abs-orbheat from the contact material in excess of that necessary for theendo'thermic'conversion reaction .and accordingly the hydrocarbonsflowing into central space 2| will be at a higher temperature than thereactants entering bed I 3. The temperature will also be higher at thispoint than desired for reaction in the next lower catalytic bed M. Thisexcess heat in the reactants'from bed 13 is utilized to vaporize theliquid reactants injected through line 23-a and spray nozzle id a sothat the temperature of the mixture passing to bed M Will be at thedesired value. The resulting vapor mixture then passes through bed 14where heat is again picked up in excess of that necessary formaintaining the catalytic conversion reaction, and after passing throughthe bed the vapors commingle with the next liquid spray introducedthrough line 2 3-b and spray nozzle 24-h. Liquid reactants are injectedat this point again in suflicient amount to reduce the temperature ofthe mixture passing to bed 15 to the desired value. The mixture thenflows through bed [5 where absorption of heat is again in excess of thatnecessary for the reaction, and the resulting reactants are again cooledafter leaving bed I5 by admixture with a third liquid spray introducedthrough line 23-c and spray nozzle .24-c before passing to catalytic bed16, etc.

By way of example, in the catalytic cracking of hydrocarbons thereactants flowing to bed l3 may have a temperature of say 800-900 F.;whereas the hydrocarbons issuing from bed l3 into central space 2| mayhave a temperature of 1000-l10o F. Sufiicient liquid reactants, at atemperature of say 200-600 F., may be introduced as quenching materialthrough spray nozzle 24a to cause the resulting vapor mixture passing tobed M to have a temperature of 800-900 F. Upon passing through bed I4,the mixture will absorb suificient heat to reach a temperature again of10U0l100 F. Similar fluctuations in temperature will occur as thereactants pass downwardly through the reactor and alternately come incontact with the spray streams and the other catalytic contact masses.

After the catalyst has become sufficiently inactivated due todeposition'of carbonaceous material in the contact mass, the on-streamoperation is stopped and the reactor is purged with an inert gas (e. g.steam) or evacuated to remove oil vapors. The catalyst is thenregenerated by blowing an oxygen-containing gas such as air or fine gasthrough the beds in any known or suitable manner to burn off thecarbonaceous matter. During the regeneration, heat is stored in themasses of contact material for utilization during the subsequenton-stream operation as eases heat of reaction and as heat for vaporizingthe hydrocarbon liquids injected between beds.

Figure 4 illustrates another form of the invention involving severalmodifications. In this case the reactor inlet is at the bottom while theoutlet is at the top, and the catalyst beds, illustrated generally a 3|,32, 33 and 34, are of increasing height in the direction from bottom totop of the reactor. The trays are of the same general design asdescribed in connection with Figure l; but in the present modificationthe central space Within each tray is open at the top but closed at thebottom. Circumferential support means, such as shown in Figure 3-A orFigure S-B, are provided for each tray, but in this case the supportmeans are positioned at the top of the annular spaces adjacent the traysrather than at the bottom. Thus, the reactants will fiow around thebottom of each tray into the annular space between the tray and theouter shell in, theme radially inward through the bed and into thecentral space and then out of the central space at the top of the tray.Another feature of the present modification is that the trays also varyprogressively in diameter with the lowermost tray having the smallestdiameter and the uppermost tray the largest. The upper support rings,which are secured to the trays to form a portion of the circumferentialsupport means, also increase in outside diameter from the lowermost trayto the uppermost tray; and each of these support rings has an outsidediameter which is less than the inside diameter of the lower sup-portring which is positioned adjacent the tray next thereabove. Thisarrangement permits the trays to be removed from the outer shell ID incase it should become desirable to do so for any reason, by removing theupper head portion 38 of the shell and then withdrawing the trayssuccessively from the top of the reactor.

Still another feature of the modified form of reactor shown in Figure 4comprises an improved means for introducing the liquid reactants asspray between the beds. As shown in Figure 4, a T-shaped conduit memberis connected to the top of each tray (except the uppermost tray) so asto form an extension of the inner perforate wall of the tray, thesemembers being illustrated generally at 35. 36 and 31. Spray nozzles forintroducing liquid reactants are positioned within the arms of theT-shaped member in such mannor that the spray streams will be injectedtherein against each other. Thus, spray nozzles 39-aand 39b areoppositely disposed within member 35, spray nozzles 4ll-a and 4U-b areoppositely disposed within member 36 and spray nozzles 4l-a and 4l-b aresimilarly positioned within member 31. This arrangement permits the T-shaped members to serve as spray chambers and causes a more effectivecontacting of the liquid spray with the vapors. thereby insuring morerapid vaporization of the iniectecl liquid reactants. Another advanta eis that contact between the relatively cold liouid spray and the hotmetal of the trays or the outer shell is prevented. thereby reducing thestress or strain to which the equipment may be subjected due totemperature changes. Suitable provisions should be made,

of course, for permitting removal of the spray nozzles and connectinglines from the reactor for inspection and also to facilitate withdrawalof trays from the reactor whenever it becomes desirable to remove thetrays.

It is apparent that the flow of reactants through the reactorillustrated in Figure 4 will be from the side annular space of each traythrough the bed in a generally horizontal direction and into the centralspace within the tray, thence upwardly through the T-shaped spraychamber to the side annular space of the next higher tray, etc.

Figure 5 shows another modification wherein the general direction offlow of the reactants is again from bottom to top of the reactor as inFigure l. Likewise the trays, indicated generally at 52, 53, 54 and 55,increase both in height and in diameter from'bottom to top of theapparatus. Also, the circumferential support means are of the typedescribed in connection with Figure 4, the upper support ring for eachtray being of smaller outside diameter than the inside diameter of thelower support ring adjacent the next higher tray in order to permit atray to pass through any of the lower support rings for the traysthereabove so that the trays may be withdrawn from the top ofthe-apparatus. In the present modification, however, the circumferentialsupport means for the trays (indicated generally at 42, 43, 44 and 45)are positioned at the bottom of the annular spaces between the trays andthe outer shell rather than at the top. The top of the annular spaceadjacent each tray (except the uppermost tray) is closed by a circularmember 45, which preferably is designed to function also as an expansionjoint to allow for changes in temperature within the apparatus. Member46 need not be descriped in detail, inasmuch as such expansion jointsare well known to the art.

Referring further to Figure 5, the central space within each tray isclosed at the top but open at the bottom on the same manner as shown inFigure 1. Conduit means positioned externally of the reactor areprovided for the flow of fluid from the annular space adjacent each bedto the space within the reactor between the bed and the next higher bed.Thus, conduit 4! provides communication from bed 52 to bed 53; conduit48 likewise provides communication between bed 53 and bed 54; andconduit 49 similarly serves as a passageway for the flow of vapors frombed 54 to bed 55. Spray nozzles 50, 5| and 52 are positioned,respectively, in conduits 41, 48 and 43 to provide for the introductionof liquid reactants as a spray into the vapor streams flowing betweenbeds.

In the reactor of Figure 5, the flow of reactants will be into thebottom of the central space within each tray and then through the bed ina generally horizontal direction to the side annular space, thencethrough the external conduit leading to the next higher bed and into thecentral space within such next higher bed, etc.

Figure 6 shows another modification of the reactor which is similar tothe modification of Figure 5 but in which the va-porous reactants areintroduced at the top of the reactor through nozzle 5E] and flowdownwardly and out through nozzle 59 at the bottom. The catalyst trays,indicated generally at 62, 63, 64 and 55, increase in height in thedirection from the uppermost to the lowermost tray. The central spacewithin each tray is open at the top but is closed at the bottom by meansof the convex bottom member of the tray. The annular space adjacent eachtray is closed at the top by means of suitable expansion joints 46,except in the case of the bottom tray 65 where the top of the annularspace is closed by means of the circumferential support means shown at66; while the bottom of ,space adjacent the next each annular space(except for the lowermost tray) is closed by means of thecircumferential support rings indicated generally at 13, 14 and I5.Conduits 61, 68 and 65 provide passageways for the flow of reactantsfrom the side annular spaces adjacent the beds to the space above thenext lower bed. Spray nozzles 10, H and 12 are positioned withinconduits 61, 68 and 69, respectively, for introducing the liquid spraystreams into and against the vapor streams flowing within the conduits.

It is apparent that the reactant vapors will pass through the reactor ofFigure 6 by flowing downwardly into the central annular space of theupper bed, passing radially outward through the bed into the sideannular space and then flowing through the external conduit to thecentral space of the next lower bed, etc.

It will be understood that in the above description various details ofconstruction representing good engineering practice have been omitted,since they will be readily apparent to one skilled in the art. Forinstance, it is apparent that suitable manholes may be provided foraccess to the inside of the reactor and that means should be providedfor filling and emptying the trays with contact materials. Likewise,suitable insulating means should be included. Also, it will beunderstood that the drawings are merely representative of certainembodiments and that numerous specific modifications may be made withoutdeparting from the scope of the invention.

I claim:

1. Catalytic reaction apparatus for conducting alternate endothermic andexothermic reactions which comprises a vertically elongated cylindri calouter shell having an inlet and an outlet at opposite ends thereof, aplurality of annular shaped trays superposed within said shellessentially concentric thereto and in spaced apart relation to eachother and adapted each to retain a bed of granular contact material,each of said trays comprising an outer perforate wall of lesser diameterthan said outer shell so as to provide an annular space at the outerside of the tray and an inner perforate wall defining the inner side ofthe tray, an imperforate top cover member for each tray, an imperforateconvex bottom member for each tray adapted to carry the weight of thebed without direct support from beneath the bed, circumferential supportmeans for each tray positioned within said outer annular space at oneend thereof and adapted to support the weight of the tray upon saidouter shell and also to close off said outer annular space at said oneend thereof, means for directing the flow of reactants so as to causethe reactants to enter each bed from one of the side spaces and flowtherethrough in a generally horizontal direction to the other side spaceand thence to the inlet side bed and spray means positioned in the pathof flow between trays for {introduction of liquid reactants into theflowing ,stream in the form of a fine spray.

2. Apparatus according to claim 1 wherein {each of said circumferentialsupport means com- ;prises a support ring secured to said outer shelland having an inner diameter greater than the outer diameter of the traywhich it supports and a second support ring secured to the outer wall ofthe tray and having an outer diameter greater than the inner diameter ofthe first-named support ring, said second support ring being adapted torest upon the first-named support ring.

3. Apparatus according to claim 1 wherein each tray has an outerdiameter less than that of the tray next thereabove and wherein each ofsaid circumferential support means comprises a support ring secured tosaid outer shell and having an inner diameter greater than the outerdiameter of the tray which it supports and a second support ring securedto the outer wall of the tray and having an outer diameter greater thanthe inner diameter of the first-named support ring but less than theinner diameter of the first-named support ring which is adjacent thetray next thereabove, said second support ring being adapted to restupon the first-named support ring.

4. Catalytic reaction apparatus for conducting alternate endothermic andexothermic reactions which comprises a vertically elongated cylindricalouter shell having an inlet and an outlet at opposite ends thereof, aplurality of annular shaped trays superposed within said shellessentially concentric thereto and in spaced apart relation to eachother and adapted each to retain a bed of granular contact material,each of said trays comprising an outer perforate wall of lesser diameterthan said outer shell so as to provide an annular space at the outerside of the tray and an inner perforate wall defining the inner side ofthe tray and each of said trays having an outer diameter less than thatof the tray next thereaboue, an imperf-orate top cover member for eachtray, an imperforate bottom member for each tray, circumferentialsupport means for each tray positioned within said outer annular spaceat one end thereof and adapted to support the weight of the tray uponsaid outer shell and also to close 017 said outer annular space at saidone end thereof, each of said circumferential support means comprising asupport ring secured to said outer shell and having an inner diametergreater than the outer diameter of the tray which it supports and asecond support ring secured to the outer wall of the tray and having anouter diameter greater than the inner diameter of the first-namedsupport ring but less than the inner diameter of the first-named supportring which is adjacent the tray next thereaboue, said second supportring being adapted to rest upon the first-named support ring, means fordirecting the flow of reactants so as to cause the reactants to entereach bed from one of the side spaces and flow therethrough in agenerally horizontal direction to the other side space and thence to theinlet side space adjacent the next bed and spray means positioned in thepath of flow between trays for introduction of liquid reactants into theflowing stream in the form of fine spray.

HARRY F. PETERS.

No references cited.

